An escaped political prisoner and a stuffy law professor vie for the hand of a spirited schoolteacher.

When a fire destroys his mill and kills foreman Clyde Bracken, mill owner Andrew Holmes accuses rabble rouser Leopold Dilg of arson. After he is indicted for arson and murder, Dilg, certain that he will be convicted, overpowers a guard one rainy night and escapes from his cell. Pursued by the police, Dilg seeks refuge in an unoccupied cottage owned by schoolteacher Nora Shelley and her mother. Nora is alone at the house, busily preparing it for the arrival of her summer tenant, law school dean Michael Lightcap, who is looking forward to writing his new law treatise in the solitude of the Sweetbrook house. Suffering from an injured ankle, friendless and unjustly accused, Dilg breaks into the house and pleads for Nora's help. When Lightcap arrives, one day ahead of schedule, Nora hides Dilg in the attic, and after showing the professor around the house, she pretends to leave. Instead, Nora sneaks into the attic, and when Lightcap finds her slinking through the hallway, she claims that she has had a fight with her mother and asks to spend the night. The next morning, Nora's mother pounds at the door, looking for her errant daughter. She is followed by reporter Donald Forrester, who is seeking Lightcap's opinion on the Dilg case, and Dilg's attorney, Sam Yates, who has been summoned by Nora. When Yates, a former classmate of Lightcap's, declares that his client has been framed and asks for Lightcap's help, the professor avers that his interest is in the principle of the law and not in local squabbles. After Yates leaves, Nora runs after him and informs him that his client is hiding in her attic. When Yates encourages Nora to allow Dilg to hide there, she realizes that she must also remain in the house and convinces Lightcap to hire her as his cook and secretary until his valet arrives. As Lightcap dictates his sterile theories to Nora, Dilg sneaks into the kitchen, looking for something to eat. When he overhears Lightcap expounding his legal principles, Dilg brazenly steps into the room and criticizes the professor's view of the law as too abstract and idealized. Shocked at the intrusion, Nora introduces Dilg as her gardener, Joseph. Soon after, Senator James Boyd arrives with news that in the fall the President intends to appoint Lightcap to the Supreme Court. Believing that Lightcap's approach to the law is too theoretical, Dilg decides to "thaw him out" by involving the professor in his own case. At breakfast the next morning, Dilg discusses the political corruption that permeates Sweetbrook and then suggests that Nora accompany Lightcap to a local baseball game. At the game, Lightcap meets Judge Grunstadt and is shocked when the judge boasts that he has formed his opinion of Dilg's case without hearing all the evidence. Lightcap begins to admire Dilg's intelligence, but when Dilg challenges him to act against the judge, he refuses. Later, Holmes, the mill owner, campaigns to incite mob violence against the missing Dilg, so Dilg arranges for Nora to escort Lightcap downtown to the factory so that he can witness Holmes's tactics. While passing Dilg's favorite borscht shop, Lightcap, who has grown quite fond of his adversarial gardener, steps in to buy him some soup. When Lightcap makes the unusual request of adding an egg to the broth, the shop's proprietor, Jan Pulaski, realizes that the soup is destined for Dilg, the only person to ask for the added egg, and decides to follow Nora and the professor. At the factory gates, Lightcap meets Holmes, who is in the midst of introducing the crowd to Regina Bush, the grieving sweetheart of arson victim Clyde Bracken. After Nora and the professor leave the factory, Pulaski follows them back to the house and then informs the police. At dinner that night, Lightcap presents the borscht to Dilg, and when he unwraps the newspaper protecting the bottle, he sees a photograph of Dilg on the front page. Asserting that it is his duty to notify the police, Lightcap reaches for the phone, but Dilg knocks him out just as the squad cars, acting on Pulaski's information, arrive. After Dilg escapes, the police interrogate Nora and Lightcap, and although the professor is furious with Nora for involving him in Dilg's predicament, he helps her by lying that he bought the borscht for himself and that he had never seen Dilg before that day. Agitated, Lightcap visits Yates and when the lawyer shows him a fire inspection certificate signed by Bracken, the professor begins to suspect that something is amiss. Deciding to conduct his own investigation, Lightcap shaves off his beard and goes to Regina's beauty parlor for a manicure. Regina fails to recognize the now beardless Lightcap, and when she begins to flirt with him, he invites her to go dancing. Later Regina shows Lightcap a letter she received from Bracken and admits that the foreman is living in Boston. As Lightcap dances with Miss Bush, Nora, who has been searching for Dilg, realizes that he must be hiding at the house and goes to find him. Upon returning home from his date, Lightcap informs Nora that Bracken is in Boston and proposes depositing Dilg at the police station while they drive to Boston to search for Bracken. Lightcap changes his mind, however, when he learns from a police officer that the department intends to turn Dilg over to the crowd as soon as he is captured. Taking the law into his own hands, Lightcap proceeds to Boston, where he and Dilg confront Bracken when he comes to pick up his mail at the post office. After forcing Bracken to confess that he and Holmes set fire to the factory to collect the insurance, they all drive back to Sweetbrook. When Dilg insists on escorting Bracken to city hall to spare Lightcap from scandal, the two begin to argue again, and in the confusion, Bracken knocks out his captors and escapes. After the police arrest Dilg, the senator warns Lightcap to drop the case. Instead, Lightcap picks up a gun, breaks his way into Regina's beauty shop and apprehends Bracken. As the mob swarms into Dilg's hearing at the courthouse, Lightcap appears, fires his gun, produces Bracken and admonishes the crowd to uphold the law. After Dilg is exonerated, Lightcap is appointed to the Supreme Court, and Nora travels to Washington to see his opening session. Before taking his seat on the bench, Lightcap advises Nora to marry Dilg. In the courtroom, Nora spies Dilg in the audience and winks at Lightcap. Dilg thinks that she is in love with the judge and leaves, but Nora follows him. When Dilg urges her to marry Lightcap, she kisses him, and he grabs her wrist and yanks her out of the courthouse.